Pei Xiaomei, Zhang Sheng, Zhang Wanqing, Liu Pei, Song Binglei, Jiang Jianzhong, Cui Zhenggang, Binks Bernard P
The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, P. R. China.
Department of Chemistry, University of Hull, Hull, HU6 7RX, UK.
Angew Chem Int Ed Engl. 2021 Mar 1;60(10):5235-5239. doi: 10.1002/anie.202013443. Epub 2021 Jan 18.
Newly structured pH-responsive smart surfactants (N -(n)-N, n=14, 16) from alkyl trimethylammonium bromides are reported. In neutral and alkaline media N -(n)-N behaves as a normal cationic surfactant and stabilizes conventional emulsions alone, as well as Pickering emulsions and oil-in-dispersion emulsions together with oppositely and similarly charged nanoparticles, respectively. In acidic media N -(n)-N becomes a hydrophilic Bola-type surfactant, N -(n)-NH , and is an inferior emulsifier either when used alone or together with charged nanoparticles, resulting in demulsification. N -(n)-NH returns to the aqueous phase alone or together with nanoparticles after demulsification without contaminating the oil phase, and the aqueous phase can be recycled when triggered by pH change. This protocol is a green process and leads to preparation of various temporarily stable emulsions which are often used in emulsion polymerization, heterogeneous catalysis, and oil transportation.
报道了由烷基三甲基溴化铵制备的新型结构pH响应型智能表面活性剂（N-(n)-N，n = 14, 16）。在中性和碱性介质中，N-(n)-N表现为普通阳离子表面活性剂，可单独稳定传统乳液，以及分别与带相反电荷和相同电荷的纳米颗粒一起稳定Pickering乳液和分散油乳液。在酸性介质中，N-(n)-N变成亲水性Bola型表面活性剂N-(n)-NH ，单独使用或与带电纳米颗粒一起使用时都是较差的乳化剂，导致破乳。破乳后，N-(n)-NH 单独或与纳米颗粒一起返回水相，不污染油相，当由pH变化触发时，水相可循环利用。该方案是一个绿色过程，可制备各种临时稳定的乳液，这些乳液常用于乳液聚合、多相催化和石油运输。
